Most modern demographic analysis is framed by the , which describes the historical shift from high birth and death rates to low ones as societies develop.
: Birth rates begin to fall as society urbanizes and education (especially for women) increases. Demography: The Study of Human Population
: Both rates are low; the population stabilizes. Most modern demographic analysis is framed by the
: Birth rates fall below death rates, leading to an aging and potentially shrinking population—a stage now characterizing many advanced economies like Japan and Italy. Demography: The Study of Human Population
: The incidence of death in a population. Improvements in healthcare and nutrition have led to a significant increase in global life expectancy, which rose by over eight years between 1995 and 2026.